Routine Space Environment Product Issued Weekly
Issued by NWS

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1
390
FXXX02 KWNP 010226
WEKFOR

:Product: 27-day Space Weather Forecast
:Issued: 2025 Dec 01 0212 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# https://www.swpc.noaa.gov/content/subscription-services
#
#               27-day Space Weather Forecast
#
Forecast of Solar and Geomagnetic Activity
01 December - 27 December 2025

Solar activity is likely to reach moderate to high levels during the
outlook period. M-class flares (R1-R2/Minor-Moderate) are likely,
with slight chance for X-flares (R3-Strong or greater), through 12
Dec due primarily to the flare potential of Region 4294.

There exists a slight chance for the greater than 10 MeV proton flux
to reach S1 (Minor) solar radiation storm levels through 12 Dec, due
primarily to the eruptive potential of Region 4294.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to reach high levels on 01-06, 16-17, and 24-27 Dec. Normal
to moderate levels are expected to prevail throughout the remainder
of the outlook period.

Geomagnetic activity is likely to reach active levels on 03 and 06
Dec, and G1 (Minor) storm levels on 04-05 Dec, driven by influences
from a negative polarity CH HSS. Additional G1 storm periods are
likely on 13 Dec, with active levels likely on 14 Dec, again
associated with negative polarity CH HSS effects. Active conditions
are likely on 21 Dec, followed by G1 storm levels on 22 Dec, in
response to negative polarity CH HSS influences. Further G1 storm
periods are likely on 23-26 Dec, with active levels likely on 27
Dec, due to positive polarity CH HSS influences. Quiet and quiet to
unsettled conditions are expected to prevail throughout the
remainder of the outlook period.